Tuesday, 24 November 2009

Our cover story this issue sees the great British polymath Raymond Tallis rail against the reductionist way in which neuroscience is viewed as the key to understanding human behaviour. One of his specific targets is the notoin of the 'social brian' that is underpinning research into social policy. Matt Grist, who runs the 'social brain' programme at the Royal Society for the Arts in London, has now answered back.

Tallis says: "Consider something as elementary as seeing something in front of you. While it is easy to understand how the brain, understood as a material object, would respond with nerve impulses to light falling upon it, it is not possible to explain how those nerve impulses then become a representation of the source of that light; how the effects of light in the brain reach back in a counter-causal way to the object from which the light originated."[My emphasis]

Tallis seems to have some deeply confused ideas about physical processes.

Tallis says: "The brain, as understood by neuroscience, is a piece of matter tingling with electrochemical activity. There is nothing in this activity that would make the stand-alone brain capable of making the material objects around it have an appearance to it or able to have the sense of itself as the subject to whom these objects appear."

Just like there is nothing in chemistry that can explain the epidemiology of viruses. And there is nothing in the geometry of doped regions of silicon that can explain the playing of a youtube clip. Our understanding of complex systems has to be built in layers. We don't have the brain power to understand every process simultaneously at every level of abstraction.

The "electrochemical activity" that Tallis refers to is indeed too low a level to understand "sense", "itself", "subject" etc. But this is a strawman argument. Neuroscience proceeds at multiple levels. Nobody working in the field is expecting a full understanding of the human condition expressed in the migration of individual ions.

Mr. Tallis states that we are not our brains, yet fails to follow this up with any argument or evidence, leaving one to wonder what Mr. Tallis then thinks we are? If our minds are not the result of biological processes in our brains, does Mr. Tallis believe there is some non-physical aspect to our consciousness? Something separate from our physical bodies? This reeks of religiosity and has no basis in science.

Mr. Tallis also dismisses Benjamin Libet's groundbreaking research about the power of the subconscious mind as "ludicrously over-interpreted", failing tyo acknowledge the mountains of research data generated since Libet's first experiments in the 1980's that point to the exact same conclusion - that the subconscious part of our mind, so vastly more potent and capable than the thin veneer of consciousness claiming to call the shots, is really responsible for the majority of our decision-making processes. This case is made eloquently and backed by incredible amounts of research in Ap Dijksterhuis's 2007 book 'Het Slimme Onderbewuste', which is unfortunately still awaiting an English translation.

Mr. Tallis does a lot of whinging in his piece, but fails to provide a single viable counterpoint. Instead he complains ceaselessly about what things are not, in his opinion, and neglects to state what he then believes things are.

"When neuroscientists started mapping how the brain works, they expected to find the relatively newly evolved neo-cortex (seat of controlled and goal-oriented behaviour, amongst other things) responsible for most of what we do. In fact, they discovered that much of our behaviour is mediated through automatic brain functions"

The gist of much of the current neuro-work is that correlating activity in the brain immediately leads to causality. This is fallacious in two ways:

First and most obvious, correlation is not causality.

Second, the experimental methods used are simply mapping crude levels of activity, not the more subtle, interpretation laden, human aspects of neurological function.

In effect, what researchers are doing is taking a thermograph of the inside of a laptop computer and proclaiming that they understand the line-by-line nature of the program source code that's running on it based on the heat output of the chips.

Scott A. Morris said "In effect, what researchers are doing is taking a thermograph of the inside of a laptop computer and proclaiming that they understand the line-by-line nature of the program source code that's running on it based on the heat output of the chips."

I think such a statement would be best accompanied by references to particular papers by particular researchers. Your accusation sounds much more suited to the general run of newspaper science writers.

No. I've read the occasional column by Ben (probably linked from a skeptics blog) and I appreciate his work. There are some wonderful science journalists out there, e.g., Carl Zimmer, but I fear the public understanding of science is not well served by most of what passes for science news.

Our consciousness and self-awareness can be completely explained in terms of abilities we share with the simplest of creatures. Furthermore, many of the things we consider important about consciousness and humanity do not require either of them: emotion, intelligence, knowledge of the self and others, family and companionship, culture, and even personality.

What foolishness. Because humans do things with their brains that other animals don't, the human brain cannot be explained materially? Well then, I suppose the orangutan arm must be unexplainable as well considering that mice cannot brachiate. It does not follow that, simply because a certain organ in a certain animal has reached a level of sophistication, interrelation, and innovative function not found, exactly, in other life-forms, the function in question cannot have a material base in that organ. This argument is merely metaphysical special pleading.

First, Tallis wants to differentiate humans from animals because we have deliberately created structures and have been influenced by them; in other words, we have "culture". Of course, he refuses to believe that other animals have created cultures of their own. The social worlds of the wolves, gorillas, or whales may be primitive or alien. But they exist nonetheless.

Second, cultures that are separated diverge. If being human means belonging to some web of thought, then what is someone who belongs to an entirely different web of thought? One could of course argue for the fundamental constants of any culture, but would have a hard time justifying it without resorting to stuff like neuroscience or evolutionary biology.

Third, there are humans who do not actively engage in culture to the extent that others do. For example, some suffer from brain damage. Though presumably Tallis would like to include them in the circle of humanity, his definition is no more expansive than a neuroscientist's.

This is not a particularly well-written article, and it obviously is trying to sneak a distinct metaphysical perspective in the back door.

Neuroscience can tell us that each of our behaviors, experiences, emotions, etc. are mediated by certain regions of the brain. Of course it can be very tricky to design stimuli so that you're really controlling for the things you think you are, and I expect that many of the cognitive events attributed to a region or two will be discovered over time to be underlaid by rather complex networks. But there is no inexplicable leap in the advanced human abilities for introspection, problem-solving, emotion, error detection and correction, even self-awareness. While most animals do not show many of those cognitive abilities, a thorough study of the primate literature makes it clear just how fluid the boundaries are between humans and other animals.

Where I do get off the "neuro-hyphen" bus is in thinking it makes much sense to use the information that the brain mediates all of our experiences as a basis for making decisions in *most* other disciplines. At the end of the day the foundations of our society, legal system, etc. tend to be based on the idea of people as volitional agents. After taking a neurophilosophy course several years ago I still really don't see a way to redesign these systems in a better manner. However, we can and should have a long debate about whether different degrees of abnormal brain functioning limit culpability for actions. With our present tools that is a very difficult judgment to make in most cases, and can be a very slippery slope.

Finally, I will also admit that I remain skeptical of the power of neuroscience to explain the fact that we subjectively experience all of these processes of our brain. The best argument I have seen is that consciousness is a byproduct of the "binding problem" of filtering and integrating stimuli. However, that still does not address the question of how subjectively experiencing that integrated/filtered result is evolutionarily advantageous.

As a rehabilitation researcher I hope he is familiar with "The Body Has a Mind of Its Own: How Body Maps in Your Brain Help You Do (Almost) Everything Better" and "The Brain That Changes Itself: Stories of Personal Triumph from the Frontier of Brain Science".

While I strongly agree that there is allot of pseudo science and hype I also strongly associate with the materialist paradigm. Yes there are many gaps in our knowledge and we don't spend much serious money studying how the brain works in general. Because the brain often malfunctions we do spend allot of money trying to fix it and in the process we dispel allot of folk psychology. If you start out with the proposition that the materialist paradigm can never fill in the gaps in our knowledge about the brain you deny the paradigm of science and rely on your ability to see the future. "Physiological Psychology" by Robert Graham is a slightly outdated but well written great background source. "The Feeling of What Happens" by Antonio Damasio is challenging but deeply rewarding book. He predicts and characterizes cortical maps for the visceral organs before they were found. Neural nets may not be a complete brain paradigm but they are a model with powerful insight.

The attack on altruism holds sway for most scientists and this political paradigm is unfortunate. From the biochemical perspective simple genetic determinism has always been junk science even though it dominated since E. O. Wilson (the ant guy) wrote about humans, until the human genome project found too few genes for it to be plausible. I find the blank slate paradigm to be a straw man and neural plasticity to be increasingly well documented.

Respecting each individual human because she has a brain that functions in the same manor as all others despite the folk psychology/philosophy and pseudo science to the contrary is the basis of my humanism.

I find that the morphing of Creation Science into Intelligent Design is modeled upon another simple story and how it has change names when the old name gets too much discredited baggage. The simple pre Darwinian notion of noble blood changed to to eugenics to sociobiology to evolutionary psychology and perhaps behavioral genetics may come next.

Getting back to his attack upon materialism beyond the wild west of brain scan phrenology, I find emergence and complexity theory to be key words in the vocabulary of these pseudo sciences.Curt